Spectral Characteristics of Pulse Radiation in Dispersive Nonstationary Media

摘要

Ⅰ.Introduction Transformation of radiation spectral characteristics is one of the important problem of waves propagation in a randomly-inhomogeneous nonstationary media.Mainly detailed calculations had been carried out in the approximation of nonstationary geometrical optics [1,2] at small wave amplitude fluctuations. Initial radiation is assumed either monochromatic or statistically stationary. In reality the radiation has pulsed character. Phase distortions arising at wave propagation in a randomly - inhomogeneous medium lead to the distortion of the mean field of pulse radiation. These effects had been analysed in [3,4] for dispersive and nondispersive media. Frequency - modulated signal containing wide frequency spectrum,passing in a nonstationary media is modified substantially depending on the correlation between different spectral components. The investigations of spectral characteristics of pulse radiation in nondispersive media had been carried out in [5,6] using statistical moment method [7]. The influense of temporal dispertion of a chaotically inhomogeneous medium on a running power spectrum (RPS) of the pulse signal is considered in this paper.